Estimating the Weight/Age of Fish

Is there a web site y'all use to estimate weight/age of fish by the length and whatnot. Also, is there a site that explains or judges the migratory pattern of fish? Or tells if they're territorial fish?

I've always been interested in this but reason I'm asking is because I've seen a huge Blue Marlin out here at work a few times over the past 2years or so. I was just curious if they stick around the same area or not. I also saw a smaller Blue yesterday which was clearly a different fish. I'm just kind of curious now how they behave. I've noticed AJs will come and go from here. Some divers dove a few days ago and said there was little to no life when they dove and they yesterday I had the AJs, sharks, and mangoves in a feeding frenzy on the surface.

Anyways...

Thanks in advance! PNG

Which rig do you work on? what depth?

Generally speaking, Blue Marlin do migrate away from this area during the winter to warmer waters. However, some marlin are caught around the deeper rigs every winter. the water temp at the deeper rigs doesn't dip much if any below 70 degrees during most winters. Also, the tuna stay at the rigs during the whole year, so a marlin could keep a consistent food source there.

I know Guy Harvey has tagged many marlin with tracking devices. you may be able to google this to see some of the tracks they have taken. I remember seeing that they will swim great distances to follow food sources, but they also will swim back to the same areas seasonally.

Your marlin could either be migrating away and then coming back to your rig....or there is a chance i guess that it's staying nearby because of the consistent food source next to the rig......or...maybe you are seeing multiple large marlin.

sorry...no link...just my ramblings.

I'm in the EI block. 225-250' water depth. It's basically blue water year round. I'm not sure about the temps and all that. From where I'm at it's a gradual drop to deep water. From what I have seen and read, about -/+20 miles south of our platform is over 1500' h20 depth.

I know depths, temps, food sources and all that play a big factor. I was just curious what people have seen and studied and learned and all that.

Thanks Fiver